Fluid contact columns and chemical reactors, and particularly gas-liquid contact columns, liquid-liquid or liquid-chemical reactors, are employed in a wide variety of processes to include, but not be limited to: adsorption, stripping, devolatilization scrubbing, distillation, extraction and chemical-type processes such as reactions. The fluid contact devices generally contain a main or predistributor and a plurality of lower level distributors designed to receive a liquid to be introduced into the upper section of the column and to be distributed more or less uniformly over substantially the entire cross sectional area of the column or reactor. In gas-liquid contact columns, the liquid is distributed generally with an upwardly flowing gas in the column, with the liquid removed from the lower portion of the column after contacting with the gas, and the gas removed from the top portion of the column. In chemical reactors, the liquid may be introduced in the top of the column for any type of chemical reaction or process and flow through the mass transfer devices, and more particularly, through structured packing acting as a static mixing device to ensure plug flow of the liquid downwardly through the column, and with the liquid then removed from the bottom portion of the column. Columns and reactors may contain for example a plurality of contacting zones, and such zones may comprise generally packing-type material, either random or structured-type packing, or combinations thereof, positioned to effect the efficient contact between the upwardly flowing gas and the downwardly flowing liquid or for the mixing of the downwardly flowing liquid to provide for a substantial plug flow of the liquid downwardly.
In particular, the liquid distributor apparatus generally employs a central parting box or tubular manifold as a predistributor for the liquid, which generally extends perpendicularly to a plurality of parallel arranged liquid distributor troughs or pipes. The liquid is fed in from a pipe or source into the predistributor, and from the predistributor, the liquid is fed to the plurality of liquid distributors for distribution through downwardly flowing holes in the distributor onto the top section or some zones of the reactor or column. Typically, distributors employed in contact columns are described for example in U.S. Pat. No. 4,062,524, issued Dec. 13, 1977, U.S. Pat. No. 4,816,191, issued Mar. 28, 1989 and U.S. Pat. No. 4,994,210, issued Feb. 19, 1991.
The type of packing employed in columns and reactors is typically structured packing composed of corrugated lamellas or intersecting bars and blades wherein mixing takes place within the packing elements as the liquid or liquid-gas is continually subdivided. Generally, the corrugations of adjacent lamellas, or open flow channels formed by intersecting bars or blades, are oriented in different directions, while adjacent packing element layers are angularly offset from each other. Further describing corrugated lamellas, each lamella has corrugations therein with the corrugations of sequentially arranged lamellas being oriented in different directions and with the corrugations with at least one or two sequentially arranged lamellas relative to the direction of flow being disposed at an angle at said longitudinal axis and each packing element generally angularly offset to an adjacent packing element at not more than about 90.degree.. The mixing lamella employed typically is also perforated and for example, may be composed where each lamella is made of a metal woven screen material.
Another type of structured packing comprises packing or static mixer elements having a plurality of intersecting stationary bars or blades, for example, placed lengthwise within a pipe with adjacent bar or blade elements usually positioned 90.degree. relative to each other. Such structured packing is designed to provide radial mixing and plug flow, particularly for use in chemical reactions to perform continuous chemical reactions. Plug flow of the product is desirable so that all the product passes through the reactor within a defined time period. Radial mixing is desirable to provide uniformity in flow of the product. One type of structured packing designed for high viscosity, tubular plug flow reactors is SMX.TM. packing, while SMV.TM. packing, which includes separation plates between layers to prevent large scale recirculation and back mixing, is useful for gas-liquid applications for low and moderate viscosity liquids. (SMX and SMV are trademarks of Koch Engineering Company, Inc. of Wichita, Kans.). Three plug flow-type structured packings are described for example in U.S. Pat. Nos. 3,871,624, 3,918,668 and 4,062,524.
Performance of fluid contact columns and chemical reactors is generally improved by proper distribution of the liquid feed. Particular problems arise in connection with the distribution and flow of high viscosity liquids in gas-liquid contact columns or in chemical reactors and in other downward liquid flow mixing vessels. It is therefore desirable to provide for an efficient, effective distributor apparatus and method for high viscosity liquids in fluid contact columns and chemical reactors.